Oils and waxes are usually utilized in solid or cake-like cosmetic products as binder materials in make-up preparations such as face powder, powder foundation, eye shadow, mascara, rouge and the like. Because oils and waxes are slippery, with lubricating properties, cosmetics made therewith produce the positive effects on skin, of a feel of richness and creaminess, though to some users this may feel objectionably greasy. In a negative aspect, in many instances, the oily and waxy materials tend to soil clothing and other items with which they are brought into contact.
Oils are derived from animal, vegetable and mineral sources or they can be synthesized and are generally characterized as being slippery, combustible, viscous, liquid or liquefiable at room temperatures, and are soluble in various organic solvents, such as ether but not in water. Waxes are also derived from animal, vegetable, and mineral sources and can also be synthesized and are generally similar in composition and properties to oil except that waxes contain no glycerides and are generally solid in nature (though in a very viscous form).
In a typical application such as a cake type foundation, oil content (wt. %) ranges from 3 to 15% wherein the oily components are used as binders and to increase creaminess and adhesion to the skin. Anhydrous foundation and emulsion type foundation typically contain 10 to 20% of oil, with increase of oil content serving to increase extendibility and adhesiveness of cosmetic products. However, oil components tend to retard normal physiological functions such as perspiration and respiration through the skin, particularly when the oily components are present in cosmetic products in high percentages.
Dermatological problems may be caused when the oil-containing cosmetic such as a dry skin moisturizer, clogs pores. This condition contributes to the incidence of acne vulgaris, the most common skin disorder. Increased sebum production particularly in teenagers and disturbance of follicular keratinization are believed to be the primary causes of acne. Removal of excess skin oil by frequent washing and cleaning is the most recommended method for the treatment of acne. However, application of additional oil to the face, such as with cosmetics containing high levels of oily components, tends to worsen the acne condition. In addition, use of cosmetics increases the possibility of free radical generation upon exposure to UV, which in turn causes degeneration of oils, resulting in the production of skin irritating lipid peroxide.
The terms "oil-free" and "oil-control" are used in claims made by many marketers of pressed powders. These claims are linked to products which also claim "shine-control", "matte-look", "no more shine" and/or "shine-free", face powders are traditionally used to subdue the "shine" on the faceassociated with the release of sebum (a natural oily/fatty exudate) especially when it is hot and/or humid. Since the consumer expects these powder products to live up to their claims, they should not contain any oil(s) in their formulations.
Another problem when oil is used as a binder in the production of cosmetic products, is that the oil must be uniformly dispersed so that pigments and/or extender pigments do not agglomerate since non-uniformity is problematic in the production of pressed powder cosmetic products.
Oil-free liquid foundations exist. However, oil-free, non-liquid containing, pressed powder cosmetic make-up products do not truly exist. Those non-liquid cosmetic make-up products claiming to be oil-free, commonly contain silicone and/or other similar types of materials which are properly characterized as oils.